JP2004296725A - Package for housing electronic component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a package for housing an electronic component by which an electronic device with high air tight reliability can be obtained. <P>SOLUTION: The package for housing an electronic component is provided with a mounting part 4 for mounting an electronic component 7 at the center of the upper surface of a square insulation substrate 1 and a square packaging metallized layer 2 in its outer circumferential part, and a metallic cover 6 is connected with the packaging metallized layer 2 by means of a brazing material. The central part of a pair of inner circumferential parts opposite to the packaging metallized layer 2 is projected to the mounting part 4, and such a projecting region 5 is covered with the brazing material. A joint area with the metallic cover 6 can be made large on the inner circumferential side of the packaging metallized layer 2 due to the projecting region 5, and a fillet 9 can be also formed there. Thus, the joint between the packaging metallized layer 2 and the metallic cover 6 is reinforced, and the packaging metallized layer 2 can be prevented from being peeled off from the insulation substrate 1 due to a stress generating during seam welding. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a small electronic component housing package for housing electronic components therein.
[0002]
[Prior art]
Conventionally, small electronic component housing packages for housing electronic components such as semiconductor elements and piezoelectric vibrators are made of aluminum oxide-based sintered bodies, aluminum nitride-based sintered bodies, mullite-based sintered bodies, glass ceramics, and the like. It has a concave mounting part for accommodating electronic components in the center of the upper surface of the ceramic material, and has a plurality of metallized wiring conductors extending from the inside of the mounting part to the outer peripheral part of the lower surface. An insulating substrate having a rectangular frame-shaped sealing metallization layer formed thereon, and a metal lid body joined by brazing to the sealing metallization layer on the upper surface of the insulating substrate to hermetically seal the mounting portion. I have.
[0003]
According to the conventional electronic component mounting board, the electronic component is mounted on the bottom surface of the mounting portion of the insulating substrate, and the electrodes of the electronic component are electrically connected to the metallized wiring conductor in the mounting portion by, for example, an electrical connection means such as wire bonding. By electrically connecting the metal lid to the upper surface of the metallizing layer for sealing, and then joining the metal lid by a seam welding method via a brazing material previously adhered to the lower surface of the metal lid. Electronic components are hermetically sealed inside a container including an insulating substrate and a metal lid, thereby forming an electronic device as a product.
[0004]
At the time of joining by this seam welding method, the metal lid generates heat by an electric current flowing between a pair of roller electrodes for seam welding that comes into contact with the metal lid, and the brazing material on the lower surface of the metal lid melts. A certain amount of this brazing material crawls from the upper surface of the metallizing layer to the side of the metal lid so as to form a fillet. Is firmly joined to the sealing metallization layer via the brazing material.
[0005]
[Patent Document 1]
JP 2001-291796 A
[Problems to be solved by the invention]
However, in such an electronic component storage package, the size of the electronic device has become extremely small in the order of several mm square in accordance with the demand for miniaturization of the electronic device, and the width of the metallization layer for sealing has also been increased. It has become extremely narrow at 300 μm or less. Also, the width of the metallization layer for encapsulation has become extremely narrow so that the dimensions of the electronic components to be stored can be made larger than the external dimensions of the package for storing electronic components.
[0007]
And in such an electronic component storage package in which the width of the metallizing layer for sealing is as narrow as about 0.15 to 0.45 mm, the width of the joining surface between the metallizing layer for sealing and the metal lid is narrow; The distance between the edge of the metallization layer for sealing and the edge of the metal lid is very small, for example, about 0.05 mm to 0.35 mm, and a fillet of brazing material is sufficiently formed in this narrow area. Due to difficulties, when the metal lid is joined to the metallizing layer for sealing by seam welding via brazing material, the stress generated due to the large thermal shrinkage of the metal lid after joining causes a stress on the metallizing layer for sealing. The sealing metallization layer is peeled off from the upper surface of the insulating substrate due to this stress, and the hermetic reliability of an electronic device using the electronic component housing package is significantly reduced. Door had a problem in that.
[0008]
In addition, usually, in order to form a fillet of a brazing material on the outer peripheral portion of the metallizing layer for sealing when joining the metal lid on the metallizing layer for sealing, the metallizing layer for sealing and the metal lid are Since the metal lid is slightly smaller than the outer periphery of the metallizing layer on each side, a fillet of brazing material is provided on the outer peripheral side of the metallizing layer for sealing and the metal lid. Although formed, on the inner peripheral side, the metallization layer for sealing is covered with and joined to the metal lid up to the linear edge, so that it is difficult to form a fillet, so that the metal lid is sealed. Bonding with the metallization layer for stopping is weaker on the inner peripheral side than on the outer peripheral side.
[0009]
The present invention has been devised in view of such a problem, and an object of the present invention is to thermally shrink the metal lid body after joining the metal lid body to the sealing metallized layer by a seam welding method or the like. Even if a large stress is applied to the metallization layer for sealing, the metallization layer for sealing does not peel off from the upper surface of the insulating substrate, and the hermetic sealing of the obtained electronic device is completed, and the electronic component housed inside It is an object of the present invention to provide an electronic component storage package that can obtain an electronic device with high hermetic reliability that can operate normally and stably for a long period of time.
[0010]
[Means for Solving the Problems]
The electronic component storage package of the present invention has a mounting portion for mounting an electronic component at the center of the upper surface of a rectangular insulating substrate, and has a square frame-shaped sealing metallization layer on the outer peripheral portion. An electronic component storage package in which a metal lid is joined to the metallizing layer for sealing via a brazing material, wherein a central portion of a pair of inner peripheral portions of the metallizing layer facing each other is the mounting portion side. And these protruding portions are covered with the brazing material.
[0011]
According to the electronic component storage package of the present invention, a portion protruding toward the mounting portion so as to face each other is provided at a central portion of a pair of inner peripheries of the sealing metallization layer for brazing the metal cover. Since the protruding portion is covered with a brazing material for brazing the metal lid, the protruding portion and the metal lid are formed around the metallizing layer for sealing and the outer periphery of the metal lid. After joining the metal lid to the metallization layer for sealing by the seam welding method, the stress generated due to the heat shrinkage of the metal lid is to be formed by joining the brazing filler metal to the metallized layer for sealing. However, even if the stress is applied to the metallizing layer for sealing, the stress is satisfactorily dispersed in the protruding portion of the metallizing layer for sealing and the fillet of the brazing material on the outer peripheral portion, and as a result, It is possible to firmly bond the Shokufutatai, sealing metallized layer can be effectively prevented from peeling off from the insulating substrate.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, an electronic component storage package of the present invention will be described with reference to the accompanying drawings.
[0013]
FIG. 1A is a top view showing an example of an embodiment of an electronic component storage package according to the present invention, and FIG. 1B is a sectional view thereof. In these figures, 1 is an insulating substrate, 2 is a metallizing layer for sealing, 3 is a metallized wiring conductor, 4 is a mounting portion for mounting the electronic component 7, and 5 is a mounting portion 4 of the metallizing layer 2 for sealing. Reference numeral 6 denotes a metal cover for sealing the electronic component 7.
[0014]
The insulating substrate 1 is formed by laminating three ceramic layers made of a ceramic material such as an aluminum oxide sintered body, an aluminum nitride sintered body, a mullite sintered body, and a glass ceramic. It has a square shape of about 2 to 20 mm and a thickness of about 0.5 to 3 mm. A substantially rectangular concave mounting portion 4 for mounting and housing electronic components is provided at the center of the upper surface, and tungsten, molybdenum, copper, silver, or the like extends from the mounting portion 4 to the lower surface via the side surface. A plurality of metallized wiring conductors 3 made of metallized metal powder are deposited.
[0015]
On the upper surface of the insulating substrate 1, a substantially square frame-shaped sealing metallization layer 2 made of metal powder of metal such as tungsten, molybdenum, copper, silver or the like is provided so as to surround the concave mounting portion 4. 1 is formed so as to be separated from the outer periphery by about 0.05 to 0.2 mm. In this example, the insulating substrate 1 is formed by laminating three ceramic layers, but the insulating substrate 1 may be formed by laminating four or more ceramic layers.
[0016]
If the ceramic layer is made of an aluminum oxide sintered body and the metallized wiring conductor 3 and the encapsulating metallized layer 2 are made of tungsten metallized, such an insulating substrate 1 is made of aluminum oxide, silicon oxide, magnesium oxide, An appropriate organic binder, a solvent, a plasticizer, and the like are added to and mixed with a raw material powder such as calcium oxide to form a slurry, and this is formed into a sheet by a sheet forming method such as a doctor blade method, thereby forming a plurality of ceramics. Green sheets are obtained, and then the ceramic green sheets are subjected to appropriate punching, and a metal paste to be the metallized wiring conductor 3 and the metallizing layer 2 for sealing is printed and applied. By laminating up and down and firing the laminate It is created.
[0017]
Further, the metallized wiring conductor 3 attached and formed from the bottom surface of the mounting portion 4 to the lower surface via the side surface of the insulating substrate 1 electrically connects each electrode of the electronic component 7 mounted on the mounting portion 4 to an external electric circuit. Each electrode of the electronic component 7 is electrically connected to a bottom portion of the mounting portion 4 through an electrical connection means such as wire bonding, for example. Are electrically connected to an external electric circuit board (not shown) via solder or the like.
[0018]
The exposed surface of the metallized wiring conductor 3 is provided with a material that prevents the metallized wiring conductor 3 from being oxidized and corroded and has a strong connection between the metallized wiring conductor 3 and each electrode of the electronic component 7 and a connection with the external electric circuit board. In order to do so, a nickel plating layer having a thickness of about 1 to 10 μm and a gold plating layer having a thickness of about 0.1 to 3 μm are usually sequentially applied.
[0019]
Further, the metallization layer 2 for sealing provided on the upper surface of the insulating substrate 1 so as to surround the concave mounting portion 4 joins the metal lid 6 to the insulating substrate 1 by a seam welding method via a brazing material. Function as a base metal for The metallization layer 2 for sealing has a thickness of about 10 to 30 μm and a width of each side of about 0.2 to 0.5 mm.
[0020]
In the electronic component storage package of the present invention, the central portions of a pair of inner peripheries of the metallizing layer 2 facing each other project toward the mounting portion 4. By protruding the central portions of a pair of inner peripheral portions of the metallization layer 2 for sealing toward the mounting portion 4 side in this manner, the metal cover 6 is attached to the metallization layer 2 for sealing via a brazing material. At the time of joining, the protruding portion 5 is also covered with the brazing material, and the width of the joining between the metal cover 6 and the metallization layer 2 for sealing is effectively and widely secured at the protruding portion 5. In addition, the filler material 9 of the brazing material can be formed from the upper surface and the side surface of the projecting portion 5 to the lower surface of the metal lid 6.
[0021]
Therefore, like the fillet 8 on the outer peripheral portion of the metallizing layer 2 for sealing, the metallizing layer 2 for sealing and the metal lid 6 are also provided on the upper surface and side surfaces of the protruding portion 5 via the brazing material. Since the metal cover 6 is joined to the metallizing layer 2 for sealing by a seam welding method via a brazing material, the stress generated by the heat shrinkage of the metal cover 6 is sealed. Even if the stress is applied to the metallization layer 2 for sealing, the stress is well dispersed in the fillet 9 of the brazing material formed on the protruding portion 5 of the metallization layer 2 for sealing and the fillet 8 on the outer peripheral portion of the metal lid 6. As a result, the sealing metallized layer 2 is effectively prevented from peeling off from the insulating substrate 1.
[0022]
By providing such protruding portions 5 at the central portions of a pair of inner peripheral sides of the sealing metallized layer 2 so as to face each other, the protruding portions 5 are orthogonal to and perpendicular to the pair of inner peripheral sides facing each other. In both directions, the joining between the metallizing layer 2 for sealing and the metal frame 6 can be effectively reinforced, and the metallizing layer 2 for sealing is formed by the stress when the metal lid 6 is welded. 1 can be prevented from being peeled off.
[0023]
In this case, since the protruding portion 5 is provided only on one side of the inner periphery of the metallization layer 2 for sealing, the metal cover 6 is provided between the side where the protruding portion 5 is provided and the side where the protruding portion 5 is not provided. Since the brazing strength of the sealing metallized layer 2 is greatly different, the sealing metallized layer 2 is peeled off from the side where the projecting portion 5 is not provided. On the other hand, when the protruding portions 5 are provided on a pair of opposing inner peripheries of the metallizing layer 2 for sealing, the inner and outer peripheries of the side where the pair of opposing protruding portions 5 are provided are covered with a metal cover. The brazing strength of the body 6 can be balanced, and the joining between the metallizing layer 2 for sealing and the metal frame 6 can be effectively reinforced, and the stress generated when the metal lid 6 is welded can be obtained. It is possible to prevent the metallization layer 2 for sealing from peeling off from the insulating substrate 1. Therefore, the projecting portion 5 of the metallizing layer 2 for sealing needs to be provided on a pair of inner peripheral portions facing each other. Moreover, since the peeling between the sealing metallization layer 2 and the insulating substrate 1 is particularly likely to occur on the inner peripheral side of the center of the side where the narrow bonding region continues, the protruding portion 5 is formed by the sealing metallization. It is necessary to provide it at the center of the inner periphery of the layer 2.
[0024]
When the projecting portion 5 is formed on the inner periphery of the metallizing layer 2 for sealing as described above, if the height is set to be lower than the height of the metallizing layer 2 for sealing, the projecting portion 5 is formed. Can be formed between the upper surface of the metal cover 6 and the lower surface of the metal cover 6, and the fillet 9 formed between the upper surface and the side surface of the projecting portion 5 and the lower surface of the metal cover 6 can be formed. Since it can be made larger, the joining between the metallizing layer for sealing 2 and the metal frame 6 can be more effectively reinforced, and the sealing when the metal lid 6 is welded is used. The metallized layer 2 can be more reliably prevented from peeling off from the insulating substrate 1.
[0025]
In the case where the shape of the metallization layer 2 for sealing is a rectangular frame, by forming a protruding portion 5 at the center of a pair of inner peripheries facing each other on the long side, the metal lid 6 and the metal lid 6 are formed. This is particularly effective for preventing the metal lid 6 from peeling off on the long side where the bonding strength with the metallizing layer 2 for sealing is relatively weak. Therefore, when the metallization layer 2 for sealing has a rectangular frame shape, it is preferable to form the protruding portion 5 at the center of a pair of opposed inner peripheries on the long side.
[0026]
The projecting portion 5 is preferably formed in a region where the metallized wiring conductor 3 for making an electrical connection with the electronic component 7 is not formed. By forming the metallized wiring conductor 3 in a region where the metallized wiring conductor 3 is not formed, the projecting portion 5 effectively prevents the efficient electrical connection between the metallized wiring conductor 3 and the electronic component 7 from being hindered. can do.
[0027]
In order to improve the wettability between the metallizing layer 2 for sealing and the brazing material, a nickel plating layer having a thickness of about 0.5 to 5 μm is usually provided on the surface of the metallizing layer 2 for sealing. Are attached before the metal lid 6 is joined.
[0028]
Thus, according to the electronic component storage package of the present invention as described above, the electronic component 7 is mounted in the mounting portion 4 of the insulating substrate 1 and the electrodes of the electronic component 7 and the metallized wiring conductors 3 are bonded with bonding wires or the like. After electrical connection, the metal lid 6 is joined to the metallization layer 2 for sealing via a brazing material by a seam welding method, so that an electron is placed inside a container composed of the insulating substrate 1 and the metal lid 6. By hermetically sealing the component 7, an electronic device having excellent airtight reliability can be obtained.
[0029]
It should be noted that the present invention is not limited to the above-described embodiment, and various changes may be made without departing from the scope of the present invention. For example, the shape of the insulating substrate 1 and the metallization layer 2 for sealing is not a rectangular shape but a square shape, and a pair of protruding portions are formed at central portions of a pair of inner peripheral portions of the metallization layer 2 for sealing so as to face each other. The portion 5 may be provided.
[0030]
【The invention's effect】
According to the electronic component storage package of the present invention, a portion protruding toward the mounting portion so as to face each other is provided at a central portion of a pair of inner peripheries of the sealing metallization layer for brazing the metal cover. Since the protruding portion is covered with a brazing material for brazing the metal lid, the protruding portion and the metal lid are formed around the metallizing layer for sealing and the outer periphery of the metal lid. Since the filler is formed by forming a fillet of the brazing material in the same manner as on the side, the metal lid is thermally contracted after the metal lid is joined to the metallizing layer for sealing via the brazing material by the seam welding method. Even if the stress generated by this is applied to the metallizing layer for sealing, the stress is well dispersed in the protruding portion of the metallizing layer for sealing and the fillet of the brazing material at the outer peripheral portion. Me It is possible to firmly bond the metal lid to rise layer, sealing the metallized layer can be effectively prevented from peeling off from the insulating substrate.
[0031]
Therefore, when the electronic component is sealed inside the container including the insulating substrate, the metallization layer for sealing, and the metal lid, the electronic component contained therein can be operated normally and stably for a long period of time. It becomes.
[Brief description of the drawings]
FIGS. 1A and 1B are a top view and a cross-sectional view, respectively, showing an example of an embodiment of an electronic component storage package according to the present invention.
[Explanation of symbols]
1 ... insulating substrate 2 ... metallization layer 3 for sealing ... metallized wiring conductor 4 ... mounting part 5 ... protruding part 6 ...・ Metal cover 7 ・ ・ ・ ・ ・ ・ ・ Electronic parts 8 ・ ・ ・ ・ ・ ・ ・ Fillet (outer periphery)
9 Fillet (projected part)

Claims (1)

A square-shaped insulating substrate has a mounting portion for mounting electronic components at the center of the upper surface, and has a square frame-shaped metallizing layer for sealing on the outer peripheral portion, and a metal cover is provided on the metallizing layer for sealing. An electronic component storage package in which a body is joined via a brazing material, wherein a central portion of a pair of inner peripheral portions of the sealing metallized layer protrudes toward the mounting portion, and these protruding portions are An electronic component storage package covered by the brazing material.

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